1. Field of the Invention
The present invention relates to a digital camera, and in particular, to a digital camera with a zoom lens.
2. Description of the Related Art
In general, a zoom lens of a zoom digital camera is formed with a plurality of lens groups. When a power source is turned off, the plurality of lens groups are accommodated all together within a lens barrel which is retracted within a housing of the digital camera. When the power source is turned on, a zoom motor is driven to extend the lens barrel to a predetermined reference position, and the zoom lens is set to be near to a wide position. Then, a focus lens in the zoom lens is moved to a focusing position within a space formed within the housing due to extension of the lens barrel, such that the digital camera is in a stand-by state in which photographing is possible.
Recently, there has been needed a digital camera in which the time from when the power source is turned on and a lens cover is opened by a motor to the time when the digital camera is in a state in which photographing is possible (which time is referred to as a startup time hereinafter) is short.
In order to make the start-up time shorter, at a time of start-up processing, it is effective for the extension of the lens barrel and movement of the focus lens to be carried out simultaneously. In order to carry out the extension of the lens barrel and the movement of the focus lens simultaneously, however, it is necessary to drive a zoom motor which extends the lens barrel and a focus motor which moves the focus lens simultaneously, and thus a large amount of electric energy is needed at a time of start-up processing.
As a result, when a weak battery or a battery with a small amount of charge is used as a power source, although there is sufficient electric energy for photographing, the electric energy is insufficient at a time of start-up processing. As a result, the start-up processing cannot be carried out and photographing becomes difficult.